Applied Concepts Inc ACMI007 사용자 설명서
Applied Concepts 011-0131-00 rev 2
Page 68
9.1.1.1.1.1.2 Handshake Speed Data Protocols
When a handshake (polling) protocol is selected, the Speed Sensor sends only one
speed message for each speed data request (poll) it receives from the controller.
EE Polling
The simple EE Format Request is a two byte message as shown below. The response
from the Speed Sensor is a four byte message carrying fields for live speed (in
hexadecimal) and direction. Since there is no addressing in the request message, it is
assumed that it is directed to a unit with a Speed Sensor ID of 2; and only a unit with
ID=2 responds to it. Both RS-232 and RS-485 models respond to EE Format polling.
The EE Format only reports one speed. For the Traffic Speed Sensor and Speedometer
Speed Sensor, the patrol speed is reported. For the Stationary Speed Sensor, the
strongest target speed is reported.
Refer to Section 7.9 for instructions on configuring the demo application to poll for EE
Format responses.
EE Format Request (from Controller to
Speed Sensor
)
#
Description
Value
1
Start ID
0xEE
2
Check byte
0x12 (0xEE + 0x12 = 0 (mod 256))
EE Format Response (from
Speed Sensor
to Controller)
#
Description
Value
1
Start ID
0xEE
2-3
Speed
Bit 15 – valid bit (1=valid speed)
Bit 14-13 – direction (11=away,
00=neither//fork,
01=closing
Bit 12 – unused
Bit 11-0 – speed in selected units and unit resolution
Bit 14-13 – direction (11=away,
00=neither//fork,
01=closing
Bit 12 – unused
Bit 11-0 – speed in selected units and unit resolution
4
Check byte
Bytes 1-4 sum to 0 (mod 256)
EA Polling
EA Polling Request messages are like those for EE, but they contain Destination and
Source IDs as shown below. The source ID is always 1 for the controller. The
destination ID can be any value in the range from 2 through 254, and only a Speed
Sensor with that address will respond. Its response to the EA poll is to send a single
speed message in the format selected by the Message Format setting (30): EE,
Enhanced Output, B, S, F, A, AF, D0, D1, D2, D3 or D4. Only the Stationary RS-485
model responds to EA polling.
The demo PC application does not support EA polling.